In ancient Chinese history, a long defensive structure was built to keep out invaders from the north and is now known as the Great Wall of China. Under which ruler did the first large scale construction of this wall begin?

Introduction / Context:
The Great Wall of China is one of the longest and most famous defensive structures in the world. Its purpose was to protect Chinese states and empires from invasions by northern nomadic groups. Although earlier regional walls existed, the first major effort to link these walls and build a continuous defensive line on a large scale was ordered by a single ruler. This question asks you to identify the dynasty and ruler under whom that large scale construction began.

Given Data / Assumptions:

• The structure is the Great Wall of China, built to keep out invaders from the north.
• The focus is on the first large scale construction under a single central authority.
• The options mention rulers associated with different Chinese dynasties.
• We assume basic knowledge of early Chinese imperial history.

Concept / Approach:
To answer correctly, you should recall that various states built separate border walls during the Warring States period. After China was unified, Emperor Qin Shi Huang of the Qin dynasty ordered the joining and strengthening of these walls to form a longer defensive structure. This is considered the first large scale construction phase of what later became known as the Great Wall of China. The Zhou and Chu rulers belong to earlier or regional powers, and the Han rulers came later and also repaired and extended the wall, but the initial unifying project is associated with the Qin ruler.

Step-by-Step Solution:
Step 1: Recognize that the question is about the beginning of large scale, unified construction of the Great Wall, not about every later repair or extension.Step 2: Recall that Qin Shi Huang unified China and founded the Qin dynasty in the third century BCE.Step 3: After unification, he ordered existing regional walls to be linked and new sections to be built to form a long defensive wall against northern tribes.Step 4: Remember that the Zhou and Chu rulers were part of earlier fragmented periods and not responsible for a unified national wall.Step 5: Understand that while Han rulers also worked on the wall later, the first large scale unification project is attributed to the Qin ruler, Emperor Qin Shi Huang.

Verification / Alternative check:
Most history books and encyclopedias describe the Great Wall by noting that the oldest parts already existed as state walls, but the first long continuous wall was built under Qin Shi Huang. The name China itself in some older Western texts is linked with Ch'in or Qin, highlighting the importance of this dynasty. While later dynasties such as the Han and Ming also built or rebuilt sections, exam questions that focus on the beginning of the Great Wall as a unified project almost always point to the Qin ruler. This confirms that the Qin ruler, Emperor Qin Shi Huang, is the correct answer.

Why Other Options Are Wrong:
Zhou rulers belonged to an earlier feudal dynasty that did not build a unified Great Wall under a single central imperial authority.
Chu rulers controlled one of the Warring States that may have built regional defenses, but they did not oversee the large scale unification of the wall across northern China.
Han rulers came after the Qin and extended and repaired the wall, but they did not initiate the original unified wall building campaign.

Common Pitfalls:
Students sometimes confuse various dynasties because many of them worked on walls or frontier defenses. Another pitfall is assuming that the dynasty with the longest or most visible remaining wall, such as the Ming, must have been the first to build it on a large scale. In many exam questions, however, the emphasis is on the first unification of existing walls, which is tied to the Qin ruler. Remembering the link between Qin Shi Huang and the early Great Wall will help avoid these mistakes.

Final Answer:
The first large scale construction and unification of the Great Wall of China began under the Qin ruler (Emperor Qin Shi Huang).